1. Field of the Invention
The invention relates to semiconductor devices and more specifically to semiconductor devices utilizing fused glass to form hermetic seals protecting the PN junctions and to a method for simultaneously constructing a plurality of devices on a common semiconductor wafer.
2. Description of the Prior Art
Prior art glass sealed thyristors, transistors and diodes have utilized a glass layer fused to the edge of the body of semiconductor material to form a seal protecting the PN junctions formed at the interface of regions of opposite conductivity type. A typical example of a prior art glass seal is disclosed in patent application entitled, "Glass Encapsulated Diode", by Bulent E. Yoldas, Ser. No. 897,323, now U.S. Pat. No. 4,168,960, and patent application entitled, "Glass Sealed Diode" by J. E. Johnson, Ser. No. 891,090, now U.S. Pat. No. 4,161,746, both of which are assigned to the same assignee as this application. These prior art devices utilized a body of semiconductor material having tapered edges. This results in a non-symmetrical device. Non-symmetry may increase stresses induced by changes in temperature. Additionally, the wafer was separated into individual devices prior to encapsulating the devices. This increased processing complexity in that the devices must be individually handled during the encapsulation process.